Guide Specifications
Single Phase Heat Pump
Variable Refrigerant Flow Outdoor Units
Size Range:
Nominal Cooling Capacity Range: 36,000 to 60,000 Btu/h
Nominal Heating Capacity Range: 40,000 to 66,000 Btu/h
Carrier Model Number:
38VMA---HDS3-1
Part 1 - General
1.01 SYSTEM DESCRIPTION
A.The heat pump variable refrigerant flow system is a two-pipe system consisting of a single outdoor unit, multiple indoor units of various types and capacities, individual or central indoor unit controls with on/off temperature settings, all connected by fully insulated refrigerant lines utilizing factory supplied, fully insulated, branching kits. Indoor units are connected to condensate piping that shall be terminated to the nearest drain point.
B.The system shall be fully capable of providing heating or cooling as requested by the individual indoor zones that can consist of single or multiple indoor units. The heating priority shall be the default factory setting and can be changed to cooling, a single zone priority, or cooling-only.
C.The maximum number of connected indoor units shall not exceed 9.
D.The total connected indoor unit capacity shall range between 50and 130% of the outdoor unit capacity based on indoor unit type & size selected.
1.02 QUALITY ASSURANCE
A.Units shall be listed by ETL (Engineering Testing Laboratory) and be evaluated in accordance with UL standard 1995, 4th. edition.
B.Units shall be listed in the AHRI directory.
C.All units shall meet the Federal minimum efficiency standards and be tested per AHRI 210/240 Standard.
1.03 DELIVERY, STORAGE, AND HANDLING
A.Units shall be shipped in one piece and shall be stored and handled per unit manufacturer's recommendations.
B.Units shall be lifted and moved according to manufacturer’s recommendation.
1.04 WARRANTY (For Inclusion by Specifying Engineer)
Part 2 - Products
2.01 EQUIPMENT
A.General:
Factory-assembled, single piece air-cooled outdoor unit. Contained within the unit enclosure shall be all factory wiring, piping, controls, and the inverter-driven rotarycompressor.
1.The maximum sound pressure rating for a single module shall not exceed 60.7dBA in cooling orheating.Sound pressure ratings are measured at a distance of 3.3ft out and 4.3ft up from the front of the outdoor unit.
2.The outdoor unit shall include an oversized accumulator to prevent liquid slugging.
3.The outdoor unit shall be protected by a high-pressure switch, high-pressure sensor, low-pressure switch, PC board, and inverter overload protector.
4.The outdoor unit shall be capable of operating in cooling mode down to 5°F dry bulb ambient air temperature and down to -13°F wet bulb ambient air temperature in heating.
B.Unit Cabinet:
1.Unit cabinet shall be constructed of pre-coated steel, finished on both inside and outside.
2.Unit access panels shall be removable with minimal screws and shall provide full access to the compressors, fan, and control components.
3.Compressor shall be isolated in a compartment and have an acoustic wrap to assure quiet operation.
4.The outdoor unit control panel shall include an LED display for setup and diagnostics.
5.Unit shall be capable of withstanding 500-hour salt spray test.
C.Fans:
1.Outdoor fan shall discharge air horizontally and be driven by a DC inverter variable-speed motor with 8 steps.
2.Outdoor fan motor shall be totally-enclosed with permanently-lubricated bearings.
3.Motor shall be protected by internal thermal overload protection.
4.Fan blade shall be non-metallic and shall be statically and dynamically balanced.
5.Outdoor fan shall be protected by a raised metallic protective grille.
D.Compressors:
1.Outdoor unit shall be equipped with inverter-driven asymmetric scroll compressor.
2.Compressor shall be totally enclosed in the machine compartment.
3.Compressors shall be equipped with factory mounted crankcase heater.
4.Internal overloads shall protect the compressor from over-temperature operation.
5.Motor shall be suitable for operation in an R-410A refrigerant atmosphere.
6.Compressor assembly shall be installed on rubber vibration isolators.
E.Outdoor Coil:
1.Coil shall be constructed of aluminum fins mechanically bonded to seamless copper tubes, which are cleaned, dehydrated, andsealed.
2.The coil configuration shall be L-shaped, with 2 sides providing access panels for service and maintenance.
3.The coil fins shall have a factory-applied corrosion resistant blue-fin finish.
F.Controls and Safeties:
Operating controls and safeties shall be factory selected, assembled, and tested. The minimum control functions shall include the following:
1.Controls:
a.Compressor speed to match the refrigerant flow and capacity with the system requirements.
b.Outdoor fan motor speed for higher efficiency and lower sound.
c.Oil control for improved system reliability and comfort.
d.Electronic expansion valve control for precise control of the refrigerant distribution and accurate capacity management to avoid starving any units.
2.Safeties:
The following safety devices shall be part of the outdoor unit:
a.High-pressure switch
b.Fuses
c.Crankcase heater
d.Fusible plug
e.Overcurrent relay for the compressor
f.Thermal protectors for compressor and fan motor
g.Compressor time delay
h.Overcurrent sensor
i.Compressor discharge temperature sensor
j.Compressor suction and discharge pressure sensor
G.Electrical Requirements:
1.All sizes shall utilize 208/230-1-60 (V-Ph-Hz) field power supply.
2.Two-core, stranded, shielded, twisted pair cable shall be required for communication among outdoor and indoor units.
3.All power and control wiring must be installed per NEC and all local electrical codes.
H.Refrigerant Piping and Line Lengths:
1.Piping connections shall be from the front or the side of the unit. The unit shall be capable of operating with maximum connected refrigerant line lengths up to 492 (ft) actual based on total system capacity and refrigerant amount.
2.The outdoor unit shall have the ability to operate with a maximum height of 164ft between the outdoor and the lowest indoor unit.
3.The maximum distance between the outdoor unit and the furthest fan coil shall not exceed 296ft actual or 328ft equivalent. No oil traps shall be required.
4.The system shall be capable of operating when the height difference between the upper and the lower fan coil is 49ft.
I. Auxiliary Refrigerant Components:
1.All field supplied copper tubing connecting the outdoor unit to the indoor unit shall use factory-supplied branching kits consisting of Y joints or header to ensure even refrigerant flow.
2.To ensure piping flexibility, the system shall allow having Y joints downstream of other Y joints.